AS3900 209.99.72.0/21 CIDR and IP Range Summary.ASN: 3900 - Switch LtdHost Count: 2046Addressable IPs: 2048209.99.72.0/24209.99.73.0/24209.99.74.0/24209.99.75.0/24209.99.76.0/24209.99.77.0/24209.99.78.0/24209.99.79.0/24